Particle beam irradiation apparatus having adjustable low-scattering filling chamber and particle beam therapy system

Abstract

A particle beam irradiation apparatus according to the present invention is provided with a vacuum duct that forms a vacuum region through which the charged particle beam passes, a vacuum window through which the charged particle beam is launched from the vacuum region, a scanning electromagnet that scans the charged particle beam; a monitoring apparatus including a position monitor that detects the passing position of a charged particle beam and the beam size thereof, a low-scattering gas filling chamber including the monitoring apparatus, and an irradiation management apparatus that controls irradiation of the charged particle beam; the particle beam irradiation apparatus is characterized in that the low-scattering gas filling chamber is changeably disposed in such a manner that the beam-axis-direction positional relationship between the monitoring apparatus and the vacuum window is a desired one and in that the low-scattering gas filling chamber is filled with a low-scattering gas.

The invention claimed is: 
     
       1. A particle beam irradiation apparatus that irradiates a charged particle beam accelerated by an accelerator onto an irradiation subject, the particle beam irradiation apparatus comprising:
 a vacuum duct that forms a vacuum region through which the charged particle beam passes; 
 a vacuum window that includes a nonmetallic window plate, and is provided at the downstream side of the vacuum duct and through which the charged particle beam is launched from the vacuum region; 
 a scanning electromagnet that scans the charged particle beam in a direction that is perpendicular to a beam axis; 
 a monitoring apparatus including a position monitor that detects a passing position of the charged particle beam and a beam size thereof; 
 a low-scattering gas filling chamber that covers the vacuum window and at the downstream side of which, the monitoring apparatus is disposed; and 
 an irradiation management apparatus that controls irradiation of the charged particle beam, 
 wherein a length of the low-scattering gas filling chamber is adjustable in such a manner that the monitoring apparatus is moveable in the beam-axis-direction relative to the vacuum window, and 
 wherein when the charged particle beam is irradiated, the low-scattering gas filling chamber is filled with a low-scattering gas that scatters the charged particle beam less than air does. 
 
     
     
       2. The particle beam irradiation apparatus according to  claim 1 ,
 wherein the low-scattering gas filling chamber includes the monitoring apparatus disposed at the downstream side thereof, a monitor holder that holds the monitoring apparatus, an upper seal disposed on the outer circumference of the vacuum duct, and a bellows that movably connects the upper seal with the monitor holder, and 
 wherein the monitoring apparatus is a cover of the downstream side in the low-scattering gas filling chamber. 
 
     
     
       3. The particle beam irradiation apparatus according to  claim 1 , wherein the monitoring apparatus includes a window plate so as to prevent the low-scattering gas from going downstream through the monitoring apparatus. 
     
     
       4. The particle beam irradiation apparatus according to  claim 1 , further including a low-scattering gas apparatus that supplies the low-scattering gas to and exhausts the low-scattering gas from the low-scattering gas filling chamber, wherein the low-scattering gas apparatus includes a gas supply unit that supplies the low-scattering gas to the low-scattering gas filling chamber, a volume fluctuation absorption unit that changes its volume in accordance with a fluctuation in the gas pressure of the low-scattering gas filling chamber, and a gas exhaust unit that exhausts the low-scattering gas from the low-scattering gas filling chamber. 
     
     
       5. The particle beam irradiation apparatus according to  claim 4 , wherein the gas exhaust unit includes an oil container containing an oil and a pipeline that connects the low-scattering gas filling chamber with the oil container. 
     
     
       6. The particle beam irradiation apparatus according to  claim 4 , wherein the gas exhaust unit includes a pipeline that exhausts the low-scattering gas from the low-scattering gas filling chamber to the downstream side of the monitoring apparatus. 
     
     
       7. The particle beam irradiation apparatus according to  claim 1 , further including a beam data processing apparatus that determines the beam size, based on passing position information of the charged particle beam detected by the position monitor, wherein the beam data processing apparatus includes a beam size calculation unit that calculates the beam size, based on the passing position information, and an abnormality determination unit that transmits an abnormality notification signal to the irradiation management apparatus when the difference between a planned desired beam size of the charged particle beam and the beam size calculated by the beam size calculation unit is not within the range of a determination threshold value. 
     
     
       8. A particle beam therapy system comprising:
 a beam generation apparatus that generates a charged particle beam and accelerates the charged particle beam by means of an accelerator; 
 a beam transport system that transports the charged particle beam accelerated by the accelerator; and 
 a particle beam irradiation apparatus that irradiates the charged particle beam transported by the beam transport system onto an irradiation subject, wherein the particle beam irradiation apparatus is according to  claim 1 . 
 
     
     
       9. The particle beam irradiation apparatus according to  claim 2 , wherein the monitoring apparatus includes a window plate so as to prevent the low-scattering gas from going downstream through the monitoring apparatus. 
     
     
       10. The particle beam irradiation apparatus according to  claim 2 , further including a low-scattering gas apparatus that supplies the low-scattering gas to and exhausts the low-scattering gas from the low-scattering gas filling chamber, wherein the low-scattering gas apparatus includes a gas supply unit that supplies the low-scattering gas to the low-scattering gas filling chamber, a volume fluctuation absorption unit that changes its volume in accordance with a fluctuation in the gas pressure of the low-scattering gas filling chamber, and a gas exhaust unit that exhausts the low-scattering gas from the low-scattering gas filling chamber. 
     
     
       11. The particle beam irradiation apparatus according to  claim 3 , further including a low-scattering gas apparatus that supplies the low-scattering gas to and exhausts the low-scattering gas from the low-scattering gas filling chamber, wherein the low-scattering gas apparatus includes a gas supply unit that supplies the low-scattering gas to the low-scattering gas filling chamber, a volume fluctuation absorption unit that changes its volume in accordance with a fluctuation in the gas pressure of the low-scattering gas filling chamber, and a gas exhaust unit that exhausts the low-scattering gas from the low-scattering gas filling chamber. 
     
     
       12. The particle beam irradiation apparatus according to  claim 2 , further including a beam data processing apparatus that determines the beam size, based on passing position information of the charged particle beam detected by the position monitor, wherein the beam data processing apparatus includes a beam size calculation unit that calculates the beam size, based on the passing position information, and an abnormality determination unit that transmits an abnormality notification signal to the irradiation management apparatus when the difference between a planned desired beam size of the charged particle beam and the beam size calculated by the beam size calculation unit is not within the range of a determination threshold value. 
     
     
       13. The particle beam irradiation apparatus according to  claim 3 , further including a beam data processing apparatus that determines the beam size, based on passing position information of the charged particle beam detected by the position monitor, wherein the beam data processing apparatus includes a beam size calculation unit that calculates the beam size, based on the passing position information, and an abnormality determination unit that transmits an abnormality notification signal to the irradiation management apparatus when the difference between a planned desired beam size of the charged particle beam and the beam size calculated by the beam size calculation unit is not within the range of a determination threshold value. 
     
     
       14. The particle beam irradiation apparatus according to  claim 4 , further including a beam data processing apparatus that determines the beam size, based on passing position information of the charged particle beam detected by the position monitor, wherein the beam data processing apparatus includes a beam size calculation unit that calculates the beam size, based on the passing position information, and an abnormality determination unit that transmits an abnormality notification signal to the irradiation management apparatus when the difference between a planned desired beam size of the charged particle beam and the beam size calculated by the beam size calculation unit is not within the range of a determination threshold value. 
     
     
       15. The particle beam irradiation apparatus according to  claim 5 , further including a beam data processing apparatus that determines the beam size, based on passing position information of the charged particle beam detected by the position monitor, wherein the beam data processing apparatus includes a beam size calculation unit that calculates the beam size, based on the passing position information, and an abnormality determination unit that transmits an abnormality notification signal to the irradiation management apparatus when the difference between a planned desired beam size of the charged particle beam and the beam size calculated by the beam size calculation unit is not within the range of a determination threshold value. 
     
     
       16. The particle beam irradiation apparatus according to  claim 6 , further including a beam data processing apparatus that determines the beam size, based on passing position information of the charged particle beam detected by the position monitor, wherein the beam data processing apparatus includes a beam size calculation unit that calculates the beam size, based on the passing position information, and an abnormality determination unit that transmits an abnormality notification signal to the irradiation management apparatus when the difference between a planned desired beam size of the charged particle beam and the beam size calculated by the beam size calculation unit is not within the range of a determination threshold value. 
     
     
       17. A particle beam therapy system comprising:
 a beam generation apparatus that generates a charged particle beam and accelerates the charged particle beam by means of an accelerator; 
 a beam transport system that transports the charged particle beam accelerated by the accelerator; and 
 a particle beam irradiation apparatus that irradiates the charged particle beam transported by the beam transport system onto an irradiation subject, wherein the particle beam irradiation apparatus is according to  claim 2 . 
 
     
     
       18. A particle beam therapy system comprising:
 a beam generation apparatus that generates a charged particle beam and accelerates the charged particle beam by means of an accelerator; 
 a beam transport system that transports the charged particle beam accelerated by the accelerator; and 
 a particle beam irradiation apparatus that irradiates the charged particle beam transported by the beam transport system onto an irradiation subject, wherein the particle beam irradiation apparatus is according to  claim 3 . 
 
     
     
       19. A particle beam therapy system comprising:
 a beam generation apparatus that generates a charged particle beam and accelerates the charged particle beam by means of an accelerator; 
 a beam transport system that transports the charged particle beam accelerated by the accelerator; and 
 a particle beam irradiation apparatus that irradiates the charged particle beam transported by the beam transport system onto an irradiation subject, wherein the particle beam irradiation apparatus is according to  claim 4 . 
 
     
     
       20. A particle beam therapy system comprising:
 a beam generation apparatus that generates a charged particle beam and accelerates the charged particle beam by means of an accelerator; 
 a beam transport system that transports the charged particle beam accelerated by the accelerator; and 
 a particle beam irradiation apparatus that irradiates the charged particle beam transported by the beam transport system onto an irradiation subject, wherein the particle beam irradiation apparatus is according to  claim 5 .